Fluid vibrator



Sept 9, 1953 w. P. BARNES, JR v 2,850,893

- FLUID VIBRATOR' Filed April 11, 1956 SOURCE OF FLUID PRESSURE INVENTOK W/W/am B Bar/7&5; Jn

mm, 0.0.91 9 $3M United States Patent FLUID VIBRATOR William P. Barnes, Jr., Alexandria, Va., assignor to the United States of America as represented by the Secretary of the Army Application April 11, 1956, Serial No. 577,619

3 Claims. (Cl. 73-71.6)

This invention relates to vibrators wherein the vibration is obtained by turbulent fluid flow.

In the testing of different devices such as electronic components, it is desirable to use a vibrator that produces a broad band of frequencies and that is free of magnetic fields. Although vibrators which produce a single frequency are useful for certain applications, they do not produce vibrations which resemble the random vibrations of many frequencies encountered by the device in use.

The vibrator of this invention comprises an elastically mounted holder for the device to be tested and means for causing a turbulent jet of fluid to be directed against the holder.

An object of this invention is to provide a vibrator producing a broad band of frequencies which is free of magnetic fields.

Other objects are to achieve the above with a device that is sturdy, simple, and reliable, yet cheap and easy to manufacture.

The specific nature of the invention as well as other objects, uses, and advantages thereof will clearly appear from the following description and the accompanying drawings which is an axial section of a vibrator in accordance with this invention.

In the embodiment illustrated a nozzle is attached by threads 12 through hole 13 in blind flange or plate 14. The blind flange is attached in a customary manner to a frame which in this case is a standard flanged pipe T 16. The nozzle 10 has a bore of diameter d. The outlet end 18 of the nozzle extends into the T, while the other end 20 protrudes out of the T for connection to a source 21 of fluid under pressure. The amount the nozzle extends into the T may be adjusted by screwing the nozzle relative to the blind flange 14. The opening 22 of the T 16 opposite the blind flange 14 is closed with a diaphragm 24 of flexible material such as fabricreinforced rubber. The diaphragm is clamped in place by ring 26 bolted to the flange of opening 22. The third opening 28 of the T is left open for the escape of the fluid. Holder 30 comprises a bracket 36 attached to the center of the outside of diaphragm 24 and attaching bolt 32. The device 34 to be tested is attached to bracket 36 by any appropriate means.

In operation, when a fluid under pressure passes through the nozzle 10 it is accelerated, preferably to a turbulent flow condition. As the jet of fluid passes through the air to impinge upon the head of bolt 32 of the holder it is further broken up by friction with the ice air. If the fluid is a liquid, the surface tension has an effect upon the random fluctuation with which the jet will strike the holder. The ratio of the distance s from the nozzle to the holder compared to the diameter d of the nozzle is important and should be great (about 50 to 1) so that the jet will break up into random fluctuations. The pressure of the. fluid at the source, the density and surface tension of the fluid, the diameter and length of the nozzle, the distance of the nozzle to the holder, and the characteristics of the flexible mounting of the holder, all may be varied to obtain different magnitude and frequency distribution of vibration.

It will be apparent that the embodiment shown is only exemplary and that various modifications can be made in construction, materials, and arrangement within the scope of the invention as defined in the appended claims.

I claim:

1. A vibrator comprising in combination: a frame, a holder for a device to be vibrated, a flexible member flexibly attaching said holder to said frame, a source of fluid under pressure, a nozzle means attached to said source and said frame for accelerating fluid from said source to a turbulent flow condition, said nozzle means being placed so that the turbulent flow of liquid impinges against said flexible member, said nozzle means including a nozzle having a bore whose diameter is less than $3 of the distance from said nozzle to said diaphragm.

2. A vibrator comprising in combination: a frame, a diaphragm of flexible material attached to said frame, a holder for a device to be vibrated attached to said diaphragm, a source of fluid under pressure, a nozzle means attached to said source and said frame for accelerating fluid from said source to a turbulent flow condition, said nozzle means being placed so that the turbulent flow of fluid impinges against said diaphragm, said nozzle means including a nozzle having a bore whose diameter is less than of the distance from said nozzle to said diaphragm.

3. A vibrator comprising in combination: a hollow pipe T having three openings, means coupled to said T for closing the first of said openings, a diaphragm of flexible material attached to said T and closing the second of said openings, a holder for a device to be vibrated attached to said diaphragm, a nozzle means attached to said source and extending through said first means for accelerating fluid from said source to a turbulent flow condition, said nozzle means being placed so that the turbulent flow of fluid impinges against said diaphragm, the third opening of said T being left open for the escape of said fluid after impinging on said diaphragm, said nozzle means including a nozzle having a bore Whose diameter is less than M of the distance from said nozzle to said diaphragm.

References Cited in the file of this patent UNITED STATES PATENTS 2,111,036 Wippel Mar. 15, 1938 2,554,212 Quinlan May 22, 1951 2,738,671 Fiske Mar. 20, 1956 FOREIGN PATENTS 712,609 Germany Oct. 22, 1941 

